Abstract: The experiment of herbicidal and physiological effects of Nominee (10% bispyribac-sodium) were conducted in rice field in 1997. The results showed that Nominee is an excellent post-emergente herbicide and 100% of weed control was obtained at 2 mg/m 2 application dosage during 1～5 leaf stage of rice. It was also showed that reversible inhibition effects of (Nominee) on rice vegetative growth occured. The significant different sensitivity between rice and Echunochloa crusgalli L. is due to their differences in photosynthesis rate, respiration rate and chlorophyll content.